There are various technical applications for fastening a connection bushing, such as a threaded insert, in a housing. For example, if such a housing is used in a cooling water circuit or a hydraulic circuit of a machine, such a connection bushing is used for the connection of a line containing fluid to the housing. From this it follows that the connection bushing has to be fastened in the housing pressure-tight so that no leakage in the water, oil, gas or hydraulic circuit occurs.
Currently, metallic threaded inserts are installed as connection bushing in plastic housings in various ways. These housings consist for example of thermoplastic materials with or without fiber reinforcement.
According to a known manufacturing alternative, the connection bushing is positioned during the production of the housing in the mould of the housing, and is then insert moulded or overmoulded with the selected plastic. This requires a complex construction of the shape of the housing, in which the connection bushing is not only held position-proof but is also closed by means of for example a core pin. In this manner, in addition to the forming or molding into the housing wall, it is also ensured that the interior of the connection bushing is kept free of material during the manufacturing process.
Furthermore, there exists the possibility to provide the connection bushing with a separate sealing ring, such as an O-ring, and to press it into the wall of the housing. According to a third manufacturing alternative the metallic connection bushing is inductively heated and embedded into the housing wall.
However, various disadvantages are associated with the manufacturing alternatives described above, which adversely affect in particular the pressure-tight connection between housing and connection bushing. If, for example, the sealing function is mainly realized by the O-ring, the material of the O-ring has to be adapted necessarily to the liquids to be passed through the connection bushing. Otherwise, aggressive media could cause that the O-ring is damaged and thereby the tightness is reduced. Another disadvantage often is that the O-ring material must withstand the thermal stress during the installation of the connection bushing and during the use of the connection provided by the connection bushing. Already from the compromise which is necessary with respect to the material of the sealing O-ring it results that neither an optimal resistance of the O-ring with respect to aggressive media nor an ideal temperature resistance is achieved. In addition, it is possible that the sealing ring is damaged during the pressing in because of the occurring mechanical stresses. A further disadvantage is that in the course of the operation of such a housing with connection bushing and sealing O-ring, this O-ring ages and the sealing ring material gets brittle. This embrittlement of the sealing ring material affects also adversely the tightness of the connection produced.
EP 1160071 A2 describes a friction welding method for a pin-like threaded element. Here, the pin-like threaded element is first mounted in a friction welding bushing by means of its external thread. Thereafter, the friction welding bushing is rotated via the pin-like threaded element and mounted in a channel in a friction welding manner. The channel is provided in a mounting dome as an opening in a component or as a depression in a component. As the torque for friction welding is transmitted from the pin-like threaded element to the friction welding bushing, this mechanical stress weakens the connection between pin-like threaded element and friction welding bushing. This has a negative effect on the connection to be produced finally between pin-like threaded element and component.
It is therefore an object of at least some implementations of the present invention to fasten a connection bushing, such as a threaded bushing, in a reliable and efficient manner at different locations in a housing and/or in different housings, so that this connection bushing may be used as a connection point for different purposes.